It can be easy to take our teeth for granted until something goes wrong. Our teeth play a major role in our ability to eat and digest food, and can affect our overall health.
Adults typically have 32 permanent teeth, though people who’ve had all of their wisdom teeth removed might have only 28. Some people naturally have fewer teeth, a condition called hypodontia. And others naturally have extra teeth, known as hyperdontia.
Our different types of teeth help us cut, tear, mash, and grind our food, making it easier to swallow. Here’s what you need to know about each type and its role, as well as the parts and anatomy of teeth.
Adults have four main types of teeth, each with a slightly different shape designed for its specific role.
Incisors
Incisors are the eight front teeth — four on the top and four on the bottom — with flat edges for cutting and biting food. These are the first teeth to come in, usually starting around 8 or 9 months of age. Incisors are also usually the first teeth that kids lose, typically when they’re around 6 or 7 years old. Permanent incisors tend to grow in around age 7 or 8.
Canines
Canines are the four sharp teeth on either side of the upper and lower incisors. They are the pointiest teeth and help you tear apart foods like meats or crunchy vegetables. Canines get their name because they look a lot like a dog’s fangs.
Babies usually get their upper canines around 16 to 22 months of age, followed by the lower canines at about 17 to 23 months. The lower canines tend to fall out first, between ages 9 and 12, and permanent canines also start coming in around this time.
Premolars
Premolars, also called bicuspids, typically have two points that serve as ridges for tearing, crushing, and grinding food.
Premolars are located between the canines and molars. There are four premolars on the upper jaw and four on the lower jaw. Babies don’t get bicuspids — these permanent teeth don’t start growing in until kids are around 10 years old.
Molars
Molars are the tough teeth all the way in the back of the mouth that have several points and ridges. They handle about 90 percent of your chewing. Most people grow a dozen molars, but many have fewer after the removal of their wisdom teeth, which are a type of molar.
- First Molars We use the first molars for grinding and chewing food. In the first set of teeth that a child develops, they sit right behind the canines. These start to appear when babies are about 13 to 19 months old, growing in on top first. Permanent first molars start growing in when kids are around 6 or 7 years old, first on the bottom, a few years before these baby teeth fall out.
- Second Molars The second molars are also for grinding and chewing food. These grow in a little later, around 23 to 33 months, then fall out when kids are about 10 to 12 years old. Permanent second molars grow in at about 11 to 13 years old.
- Third Molars Third molars are also known as wisdom teeth. Babies don’t have them. While some people don’t get these teeth, most people see third molars come in when they’re around 17 to 21 years old. Many adults get one or more of their wisdom teeth removed when they crowd or damage nearby teeth or stay completely or partially under the gums (known as impaction), increasing the risk of cavities and infections.
Your teeth contain four kinds of tissue, and each does a different job.
Enamel
Enamel is the white outer layer of your teeth. Harder than bone, enamel is a calcified coating that protects other tissues within a tooth.
Cementum
Cementum is the connective tissue below the gumline that covers the roots of a tooth and helps anchor it to the jaw bone. While cementum is technically hard tissue, it’s softer than enamel.
Dentin
Dentin is right underneath the enamel and cementum. It's not quite as strong as enamel, and it’s at greater risk for tooth decay when enamel wears away.
Dentin contains tubules, or small hollow canals that can become sensitive to heat, cold, or acidic or sticky foods when enamel wears away.
Pulp
Pulp is the soft layer at the center of a tooth. It contains nerves, connective tissue, and blood vessels. Pulp supplies nutrients and helps fight decay and other damage.
Teeth have two basic parts: the crown, which is the visible white part, and the root, which you can’t see. The roots extend below the gumline and help anchor teeth into the bone.
Crown
The crown is the part of a tooth that's visible above the gums. Enamel covers the crown.
Root
The root is the part of a tooth that is not visible because the gums cover it. The root attaches to many ligaments; the major one is the periodontal ligament, soft connective tissue that lines a tooth's socket.
Rachel Green
Rachel Davis
Derek Schulz
Sophia Martinez
Dr. Amara Okafor